Speeding up the ADC

I was wondering if you considered speeding up the ADC by reducing the bit depth to 8 bit... Of course I always think 10 bit is minimum in my mind, but in all seriousness, I think 8 bit would be fine, plus it would save a byte of memory as well. I can't remember exactly how it was done, there was an oscilloscope example that reduced the resolution and the were able to get like 15,000 samples/second on several channels. I think I may start looking into it, even though I have not had any issues with the processor getting bogged down